Great Deal Of Individual Variation Research Articles

Understanding the nature and impact of cognitive fluctuations and sleep disturbances in dementia with Lewy bodies: A qualitative caregiver study.

Dementia with Lewy bodies is characterised by rapid fluctuations in attention, which are known as "cognitive fluctuations." Despite the fact that cognitive fluctuations are considered to be a core dementia with Lewy bodies symptom, they are very difficult to define and measure using existing quantitative subjective measurement tools, which are typically completed by caregivers. Cognitive fluctuations are also likely to be influenced by various aspects of sleep, but this is as yet unexplored. The primary aim of this qualitative study was to investigate the phenomenology of cognitive fluctuations in dementia with Lewy bodies by understanding caregiver experiences. Seven caregivers of people with dementia with Lewy bodies completed one-to-one semistructured interviews, which were conducted by telephone. Caregivers were asked to describe the nature, frequency, duration and potential triggers of cognitive fluctuations that were experienced by the individual with dementia with Lewy bodies. Caregivers were also asked about the subjective sleep experience of the individual with dementia with Lewy bodies, and about their own sleep experiences. Interviews were audio recorded, transcribed verbatim and analysed using Thematic Analysis. Caregivers reported that there was a great deal of individual variation in the frequency, duration and severity of cognitive fluctuations. Patient sleep disturbances, including excessive daytime sleepiness, nocturnal awakenings, restless legs and sleep apnoea, were common. However, the impact of sleep alterations or experiences upon the fluctuations was reported to be less clear. Caregivers also reported that their own sleep was negatively affected, potentially due to actively listening for overnight events and behaviours. Qualitatively, caregivers report that dementia with Lewy bodies cognitive fluctuations show large individual variations in terms of their frequency, duration and severity, but that subjectively, sleep may not consistently influence this symptom. Specific, caregiver-focussed interventions are likely to be necessary to maintain good sleep health in dementia with Lewy bodies caregivers.

Adjective position in the code-switched speech of Spanish and Papiamento heritage speakers in the Netherlands: Individual differences and methodological considerations.

This study examines adjective-noun order in code-switched constructions by heritage speakers of Spanish and Papiamento in the Netherlands. Given that Dutch differs from Spanish and Papiamento regarding the default position of the adjective, word order in the nominal domain creates a so-called "conflict site" in code-switching. Most accounts of word order patterns in code-switching focus on structural constraints, such as the matrix language or the strength of the EPP feature in Agr. Thus far, studies comparing the two models have not found compelling evidence for either of them. The present study takes a more comprehensive approach and considers several linguistic (matrix language, adjective language, and type of insertion) as well as extra-linguistic variables (e.g., age, age of onset, and patterns of exposure and use). Moreover, we compare heritage speakers of two different heritage languages that are linguistically similar (both Spanish and Papiamento exhibit postnominal adjectives), and share the same dominant societal language, but are likely to differ from each other in terms of certain sociolinguistic properties. 21 Spanish and 15 Papiamento heritage speakers (aged 7-54) in the Netherlands carried out a Director-Matcher task, aimed at eliciting nominal constructions containing switches. The results show that either the ML or the language of the adjective, or both, are important predictors for word order, although the data cannot disentangle these two factors. Moreover, the type of insertion was found to play a role: word order patterns for noun insertions differed from other types of insertions. In addition, the two groups did not behave similarly: Papiamento speakers were more categorical in their preference for noun-adjective order when inserting Dutch nouns into their heritage language than the Spanish speakers were. Finally, there was a great deal of individual variation, which seemed to be related mostly to the age of the participants: children and teen participants behaved differently from adults. These findings demonstrate that both linguistic and extra-linguistic play a role in determining how heritage speakers deal with conflict sites in the nominal domain. Particularly, the findings suggest that, at least for some communities and in some code-switching modes, children may need more time, or more input, too converge on adult-like code-switching norms.

Control Beliefs, Age, and Objectification Experiences in Younger and Older Women

Control beliefs show age-related patterns; mastery decreases in adulthood, while constraints beliefs often increase. However, there is a great deal of individual variation. This paper addresses antecedents of control beliefs, with attention to experiences and beliefs related to sexual objectification, which have particular impact for women. In this study, younger women (N = 132, M = 20.93) and older women (N = 86, M = 67.83) were surveyed regarding their experiences with sexual objectification and constraints beliefs. Multiple regression analyses revealed higher self-objectification was associated with higher constraints (R2 = .09**) and lower mastery (R2 = .11**) but reports of body evaluation and sexual advances were not associated with control beliefs. Further, there were no interactions of either objectification scale with age. These results suggest that objectification may be an important part of the aging experience across the life course, not just in young adulthood.

Long-term periodontal changes associated with oral appliance treatment of obstructive sleep apnea.

To characterize the mandibular anterior teeth crown height as a marker of periodontal changes and bone loss as a side effect of an oral appliance worn for a minimum of 4.5 years. This retrospective study conducted in patients with healthy baseline periodontium recruited participants among consecutive sleep apnea patients treated with an oral appliance between 2004 to 2014. Eligible participants were recalled for a follow-up visit at which a periodontal examination was performed and a lateral cephalogram and dental impressions were obtained. Clinical crown height for mandibular anterior teeth and cephalometric variables were measured and compared before and after treatment. A full periodontal evaluation was performed at the follow-up visit. Twenty-one patients enrolled with a mean treatment length of 7.9 ± 3.3 years. For the mandibular anterior teeth, clinical crown height did not change over the evaluated period. At follow-up, all the periodontal assessed variables were within normal limits, with the mean probing depth of 1.4 ± 0.5 mm, recession 0.6 ± 1.1 mm, and clinical attachment loss 0.8 ± 1.0 mm. Compared with baseline, there was a significant proclination of mandibular incisors (mean increase of 5.1 degrees) with the continued use of an oral appliance. Gingival levels were maintained with clinically insignificant changes during the observation period. Inclination of the mandibular incisors increases significantly with the use of an oral appliance in patients with obstructive sleep apnea. Positional changes in these teeth were not associated with any measured evidence of increase in clinical crown height or gingival recession. Heda P, Alalola B, Almeida FR, Kim H, Peres BU, Pliska BT. Long-term periodontal changes associated with oral appliance treatment of obstructive sleep apnea. J Clin Sleep Med. 2021;17(10):2067-2074.

Histone deacetylase inhibitor treatment promotes spontaneous caregiving behaviour in non-aggressive virgin male mice.

The majority of mammalian species are uniparental, with the mother solely providing care for young conspecifics, although fathering behaviours can emerge under certain circumstances. For example, a great deal of individual variation in response to young pups has been reported in multiple inbred strains of laboratory male mice. Furthermore, sexual experience and subsequent cohabitation with a female conspecific can induce caregiving responses in otherwise indifferent, fearful or aggressive males. Thus, a highly conserved parental neural circuit is likely present in both sexes; however, the extent to which infants are capable of activating this circuit may vary. In support of this idea, fearful or indifferent responses toward pups in female mice are linked to greater immediate early gene (IEG) expression in a fear/defensive circuit involving the anterior hypothalamus compared to that in an approach/attraction circuit involving the ventral tegmental area. However, experience with infants, particularly in combination with histone deacetylase inhibitor (HDACi) treatment, can reverse this pattern of pup-induced activation of fear/defence circuitry and promote approach behaviour. Thus, HDACi treatment may increase the transcription of primed/poised genes that play a role in the activation and selection of a maternal approach circuit in response to pup stimuli. In the present study, we investigated whether HDACi treatment would impact behavioural response selection and associated IEG expression changes in virgin male mice that are capable of ignoring, attacking or caring for pups. The results obtained indicate that systemic HDACi treatment induces spontaneous caregiving behaviour in non-aggressive male mice and alters the pattern of pup-induced IEG expression across a fear/defensive neural circuit.

A Mixed-Methods Trial of Broad Band Noise and Nature Sounds for Tinnitus Therapy: Group and Individual Responses Modeled under the Adaptation Level Theory of Tinnitus.

Objectives: A randomized cross-over trial in 18 participants tested the hypothesis that nature sounds, with unpredictable temporal characteristics and high valence would yield greater improvement in tinnitus than constant, emotionally neutral broadband noise.Study Design: The primary outcome measure was the Tinnitus Functional Index (TFI). Secondary measures were: loudness and annoyance ratings, loudness level matches, minimum masking levels, positive and negative emotionality, attention reaction and discrimination time, anxiety, depression and stress. Each sound was administered using MP3 players with earbuds for 8 continuous weeks, with a 3 week wash-out period before crossing over to the other treatment sound. Measurements were undertaken for each arm at sound fitting, 4 and 8 weeks after administration. Qualitative interviews were conducted at each of these appointments.Results: From a baseline TFI score of 41.3, sound therapy resulted in TFI scores at 8 weeks of 35.6; broadband noise resulted in significantly greater reduction (8.2 points) after 8 weeks of sound therapy use than nature sounds (3.2 points). The positive effect of sound on tinnitus was supported by secondary outcome measures of tinnitus, emotion, attention, and psychological state, but not interviews. Tinnitus loudness level match was higher for BBN at 8 weeks; while there was little change in loudness level matches for nature sounds. There was no change in minimum masking levels following sound therapy administration. Self-reported preference for one sound over another did not correlate with changes in tinnitus.Conclusions: Modeled under an adaptation level theory framework of tinnitus perception, the results indicate that the introduction of broadband noise shifts internal adaptation level weighting away from the tinnitus signal, reducing tinnitus magnitude. Nature sounds may modify the affective components of tinnitus via a secondary, residual pathway, but this appears to be less important for sound effectiveness. The different rates of adaptation to broadband noise and nature sound by the auditory system may explain the different tinnitus loudness level matches. In addition to group effects there also appears to be a great deal of individual variation. A sound therapy framework based on adaptation level theory is proposed that accounts for individual variation in preference and response to sound.Clinical Trial Registration: www.anzctr.org.au, identifier #12616000742471.

Increasing Juvenile Coho Salmon Densities during Early Recolonization Have Not Affected Resident Coastal Cutthroat Trout Growth, Movement, or Survival

AbstractThe process of salmon colonization in the upper Cedar River and Rock Creek, Washington, following the installation of a fish ladder at Landsburg Diversion Dam in 2003, offered an opportunity to measure the effects of interspecific interactions on the dynamics of resident fish populations. Rapid recolonization by Coho Salmon Oncorhynchus kisutch provided a natural experiment to determine the influence of Coho Salmon densities on the growth, movement, and survival of resident Coastal Cutthroat Trout O. clarkii clarkii relative to other abiotic and biotic factors such as habitat quality, environmental conditions, and conspecific density. During 14 seasonal sampling events from 2005 to 2009, we PIT‐tagged 1,851 and recaptured 394 Cutthroat Trout in Rock Creek, collected habitat data, enumerated fish populations, and monitored fish movements with PIT tag antenna arrays. Trout growth varied significantly among seasons and was greatest during spring and early summer. Mean juvenile Coho Salmon density in summer and fall increased eightfold from 0.04 to 0.32 and from 0.08 to 0.68 fish/m2, respectively, approaching levels seen in established populations, but did not explain variation in trout growth, movement, or survival. Summer growth of trout parr and fry were both negatively correlated with the density of conspecifics but were positively correlated with total salmonid density. Additionally, trout parr growth was positively correlated with stream discharge, whereas trout fry growth was negatively correlated with initial size and declined during the course of the study. However, abiotic and biotic explanatory variables accounted for little of the variation in trout growth, movement, and survival, suggesting that a great deal of individual variation exists. Overall, trout were largely unaffected by Coho Salmon colonists despite large increases in juvenile Coho Salmon density, though this may change if salmon populations continue to grow.Received October 18, 2013; accepted May 5, 2014

Exploring story grammar structure in the book reading interactions of African American mothers and their preschool children: a pilot investigation.

The aim of this investigation was to identify the book reading behaviors and book reading styles of middle class African American mothers engaged in a shared book reading activity with their preschool children. To this end, the mothers and their children were videotaped reading one of three books, Julius, Grandfather and I, or Somewhere in Africa. Both maternal and child behaviors were coded for the frequency of occurrence of story grammar elements contained in their stories and maternal behaviors were also coded for their use of narrative eliciting strategies. In addition, mothers were queried about the quality and quantity of book reading/story telling interactions in the home environment. The results suggest that there is a great deal of individual variation in how mothers use the story grammar elements and narrative eliciting strategies to engage their children in a shared book reading activity. Findings are discussed in terms of suggestions for additional research and practical applications are offered on ways to optimally engage African American preschool children and African American families from diverse socioeconomic backgrounds in shared book reading interactions.

Political Animals Revisited

Political Animals Revisited

Talking while Chewing: Speaker Response to Natural Perturbation of Speech

This study looks at how the conflicting goals of chewing and speech production are reconciled by examining the acoustic and articulatory output of talking while chewing. We consider chewing to be a type of perturbation with regard to speech production, but with some important differences. Ultrasound and acoustic measurements were made while participants chewed gum and produced various utterances containing the sounds /s/, /ʃ/, and /r/. Results show a great deal of individual variation in articulation and acoustics between speakers, but consistent productions and maintenance of relative acoustic distances within speakers. Although chewing interfered with speech production, and this interference manifested itself in a variety of ways across speakers, the objectives of speech production were indirectly achieved within the constraints and variability introduced by individual chewing strategies.

Feasibility of Measuring Human Pancreatic Perfusion In Vivo Using Imaging Techniques

The objective of this study was to demonstrate the feasibility of pancreatic perfusion computed tomography (CT) and review pancreatic perfusion measurements by various imaging modalities. Dynamic CT data from 8 patients (4 men; mean age, 64.8 [SD, 12.1] years; range, 40-80 years) with normal pancreas were analyzed using 2 analytical models: the maximum-slope and compartment-model methods. Literature search was also performed. Although the perfusion value estimated by the maximum-slope method (88.1 [SD, 42.1] mL/min per 100 mL) was significantly smaller than that of the compartment-model method (127.0 [SD, 70.5]; P < 0.001), there was a linear correlation between them (r = 0.97, P < 0.001). In the literature review, 15 studies that reported the absolute values of normal pancreatic perfusion, by using perfusion CT, dynamic magnetic resonance imaging, hydrogen gas clearance method, and 15O-H2O-positron emission tomography were found. The reported mean values of normal pancreatic perfusion ranged from 38.4 to 356 mL/min per 100 mL, and there was a great deal of individual variation. Perfusion CT may provide reliable perfusion measurements of the pancreas, and the normal value was estimated at around 100 mL/min per 100 mL with a great deal of individual variation. The maximum-slope method may provide a lower perfusion value compared with the compartment-model method.

ACTIVITY OF STEROID-CONJUGATING ENZYMES IN HATCHLING RED-EARED SLIDER TURTLES EXPOSED TO BISPHENOL-A

Event Abstract Back to Event ACTIVITY OF STEROID-CONJUGATING ENZYMES IN HATCHLING RED-EARED SLIDER TURTLES EXPOSED TO BISPHENOL-A Sandrine G. Clairardin1, Ryan T. Paitz1 and Rachel M. Bowden1* 1 Illinois State University, United States Endocrine disrupting chemicals (EDCs) are a class of compounds that impact the functioning of the endocrine system. To more fully understand how EDCs affect an organism, it is important to study not only the endpoint effects of a compound, but also the transient physiological response of the organism to exposure such as the upregulation of sulfotransferases (SULT) and glucuronyltransferases (UGT), two superfamilies of hepatic enzymes. In vertebrates, SULT and UGT are the two main families of enzymes involved in phase II steroid metabolism and these same enzymes are also utilized by the body for clearance and removal of xenobiotics such as EDCs. This study aims to understand which detoxifying pathway is more prominent in EDC metabolism and whether or not the activity of these enzymes is affected by exposure to an EDC. To investigate this aim, red-eared slider (Trachemys scripta) hatchlings were injected with either Bisphenol-A or a vehicle control and livers were harvested 12, 24, or 48 hours post-injection. Liver homogenates (S9 fraction) were used for enzyme assays of SULT and UGT to quantify and compare enzyme activity. Preliminary analyses show a trend for increased enzyme activity of both SULT and UGT by 24 hours post-injection, however there appears to be a great deal of individual variation in ability to respond to exposure through increased enzyme activity. Investigating changes in enzyme activity will provide insight into mechanisms of endocrine disruption, allowing for a more complete understanding of potential threats of endocrine disruptors on humans and wildlife. (Supported by EPA STAR fellowship F09G11129 to S.G.C.) Keywords: Bisphenol-A, Estradiol, steroid conjugation, turtle Conference: NASCE 2011: The inaugural meeting of the North American Society for Comparative Endocrinology, Ann Arbor, United States, 13 Jul - 16 Jul, 2011. Presentation Type: Poster Topic: Endocrine disruption Citation: Clairardin SG, Paitz RT and Bowden RM (2011). ACTIVITY OF STEROID-CONJUGATING ENZYMES IN HATCHLING RED-EARED SLIDER TURTLES EXPOSED TO BISPHENOL-A. Front. Endocrinol. Conference Abstract: NASCE 2011: The inaugural meeting of the North American Society for Comparative Endocrinology. doi: 10.3389/conf.fendo.2011.04.00118 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 21 Jul 2011; Published Online: 09 Aug 2011. * Correspondence: Dr. Rachel M Bowden, Illinois State University, Normal, United States, rmbowde@ilstu.edu Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Sandrine G Clairardin Ryan T Paitz Rachel M Bowden Google Sandrine G Clairardin Ryan T Paitz Rachel M Bowden Google Scholar Sandrine G Clairardin Ryan T Paitz Rachel M Bowden PubMed Sandrine G Clairardin Ryan T Paitz Rachel M Bowden Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Individual Variation in Human Motor-Sensory (Rolandic) Cortex

Eloquent cortex is generally identified using a variety of techniques including direct electrical stimulation to identify motor-sensory, language, and memory cortex and somatosensory evoked potentials to identify motor-sensory cortex. It is important that these areas of cortex be identified so as to prevent damage during the course of neurosurgical procedures. Seventy epilepsy patients undergoing evaluation for epilepsy surgery with chronically implanted subdural grids were retrospectively studied using both somatosensory evoked potentials and direct electrical stimulation. Direct electrical stimulation of motor-sensory cortex elicited responses over a larger area than did somatosensory evoked potentials. A great deal of individual variation was identified using both techniques. The results presented here support previous conclusions that the concept of homunculus somatotopy (point to point representation) of the motor-sensory cortex be abandoned and that of functional mosaicism of the motor-sensory cortex replace the earlier model. The individual variation found in the human motor-sensory cortex will require a continuation of "brain mapping" to identify eloquent cortex so that these vital areas will be spared during neocortical neurosurgical procedures.

The function of the disco-muscular apparatus in the human temporomandibular joint

The morphology and function of the disco-muscular apparatus of the human TMJ is a controversial subject. Connections between the muscles which move the mandible and the "disco-capsular complex" have been described in a contradictory way. The disco-muscular apparatus is also described as being more extensive than that of the M. pterygoideus alone to include to the Mm. temporalis and masseter. However, the involvement of the latter is considered to be a peripheral variation of the normal anatomy and of little, if any, functional significance. The existence of independent relationships between the deep portions of the masseter and temporal muscles and the disco-capsular apparatus of the human TMJ is rarely discussed or explained. The morphologic findings were derived from fixed and unfixed human temporomandibular joints (TMJ) of varying ages and both sexes, whereby the functional maturity of the masticatory apparatus was taken into consideration. The results of the study show that aside from fibers originating from the superior venter of the M. pterygoideus lateralis, additional muscle or connective tissue fibers from the perimysium of the M. masseter are inserted to varying extents into the disc. The same is true for the M. temporalis, which is also directly connected to the disc via muscular or fibrous elements, or indirectly via fibers from the M. masseter. The insertion of the M. pterygoideus lateralis is always in the medial portion of the Discus articularis and those of the Mm. temporalis and masseter in the middle and lateral portions of the disc respectively. It is highly probable that a direct force transfer through the Mm. temporalis and masseter to the articular disc takes place, and that these muscles contribute to the movement of the disc during jaw movement, whereas the size and form of the muscle insertions are subject to a great deal of individual variation.

Free flight capacity determination in a sustained flight tunnel: effects of age and sexual state on the flight duration of Prostephanus truncatus

Abstract. . Adult Prostephanus truncatus (Horn) (Coleoptera: Bostrichidae) steering anemotactically upwind to a pheromone source in a wind tunnel, respond normally to, and alter their ground speed according to the direction and speed of, the movement of ground patterns beneath them. By manipulating this optomotor reaction component of their behaviour, studies were conducted on their flight duration. The results show a great deal of individual variation in flight duration, and the general data on single flights were skewed towards short flights. Pre‐reproductive and inter‐reproductive male and female beetles flew significantly longer than older beetles that had passed their peak of reproduction. There was no significant difference in the flight duration of male and female beetles at any age. The overall results suggest mat younger P. truncatus are capable of long‐distance flights, and support the proposition that flight could be important in the spread of the beetle.

The function of discomuscular relationships in the human temporomandibular joint.

The aim of this morphological study was to investigate whether muscle tissue attaches directly to the discus articularis of the human temporomandibular joint (TMJ) and to indicate the probable significance of such attachments for the function of this articulation. The macroscopic and microscopic findings were derived from fixed and unfixed human TMJ of varying ages and genders, whereby the functional maturity of the masticatory apparatus was taken into consideration. To date, the results of this study show that aside from fibers originating from the superior venter of the m. pterygoideus lateralis, additional muscle or connective tissue fibers from the perimysium of the m. masseter insert to varying extent in the disc. The same is true for the m. temporalis, which is also directly connected to the disc via muscular or fibrous elements, or indirectly via fibers from the m. masseter. The insertion of the m. pterygoideus lateralis is always in the medial portion of the discus articularis and those of the mm. temporalis and masseter, respectively, in the middle and lateral portions of the disc. It is highly probable that a direct force transfer through the mm. temporalis and masseter to the articular disc takes place, and that these muscles contribute to the movement of the disc during jaw movement, whereas the size and form of the muscle insertions are subject to a great deal of individual variation. Differences were observed between immature and mature TMJ as well as between partly and fully toothed masticatory apparatuses.

Somatosensory Cortical Evoked Potential Changes After Deformity Correction

The somatosensory cortical evoked potentials recorded during posterior spine fusion and instrumentation for 99 consecutive patients with idiopathic scoliosis, 18 years of age or younger, were retrospectively reviewed. The potentials were recorded from scalp electrodes while synchronously stimulating both tibial nerves near the ankles. Signal changes observed during consecutive 30-minute time intervals after deformity correction were analyzed. No changes in neurologic status were observed postoperatively. Latency values tended to remain constant on average. A small, but statistically significant, decrease in the first two interpeak amplitudes was observed during the first 30-minute interval after deformity correction. The first interpeak amplitude recovered, while the second remained statistically significantly decreased. No patient had a decrease of greater than 50% in both of the first two amplitudes, which persisted throughout the 60-minute interval immediately after deformity correction. This study demonstrated a tendency for somatosensory cortical evoked potential interpeak amplitudes to decrease during the first 30 minutes after deformity correction. There was a great deal of individual variation, including amplitude increases in many patients. There was no evidence supporting an association between dramatic, sustained amplitude decreases and uncomplicated deformity correction. The value of thoroughly evaluating somatosensory cortical evoked potential signal trends while making intraoperative decisions is emphasized.

Long-Term Consistency of Nutrient Intakes in Humans

Consistency of intake over time for calcium, phosphorus, protein and energy, as estimated from diet diaries, was studied prospectively in two groups of women. One group provided short-term data (n = 165), and the other, data spanning intervals of up to 20 y (n = 164). Although group average intakes changed little, there was a great deal of individual variation. Even at intervals as short as 6 m, current intake estimates accounted for only about 40% of the variance of intakes at an earlier time. Over longer intervals, the predictive value of one estimate in respect to a second deteriorated even further. Thus, across 5 y, less than 25% of the variance of all four nutrient intakes could be accounted for by current intake. The 95% confidence interval for an estimate of earlier intake based upon a later measurement was more than +/- 700 mg for calcium, the least consistent nutrient. The other three nutrients showed nearly identical interstudy consistency, with uncertainties relative to their respective means being about half as large as for calcium. These data show that accurate longitudinal estimates of intake require continuous, prospective monitoring and that current intake is not a good estimator of past intake for most nutrients, especially for calcium.

The renal excretion of pethidine administered postoperatively to male dogs

The urinary excretion of pethidine and its major metabolite, norpethidine, was investigated in four male dogs given pethidine as a postoperative analgesic. The urinary excretion of pethidine in the first 4 h after drug administration was low at 1.9% of the administered dose. The percentage of the drug excreted as norpethidine was also low at 3.7% but there was a great deal of individual variation. Urinary excretion, therefore, appears to be a minor route in the clearance of pethidine in the dog.

Determination of the temporal relationship between porcine growth hormone, serum IGF-1 and cortisol concentrations in pigs.

We found previously that porcine growth hormone (pGH) causes an increase in growth rate with a concurrent improvement in carcass composition in pigs. The somatomedin, insulin-like growth factor 1 (IGF-1), is though to play a major role in mediating some of the anabolic actions of GH, while the glucocorticoid hormones are potential counter-regulators of these effects. The present study was conducted to determine the temporal and dose-response relationship between GH administration and serum IGF-1 and cortisol concentrations in pigs. Twelve Yorkshire barrows, fitted with femoral artery catheters, were injected (im) with either 0, 10, 100 or 1,000 micrograms/kg pGH. Blood sampling began 40 min prior to pGH injection and was continued for 37 h. Serum GH, IGF-1 and cortisol concentrations were determined by radioimmunoassay. In control animals, serum GH concentrations ranged from 1.6 to 5.7 ng/ml over 37 h. In the animals treated with increasing doses of pGH, peak serum GH concentrations reached 28, 112 and 286 ng/ml and levels remained elevated for 4, 12 and 24 h, respectively. Serum IGF-1 concentrations were elevated by pGH after a lag time of 4 to 6 h. When the IGF-1 concentrations were integrated over time, the response appeared to be dose-dependent, with an ED50 of 710 micrograms/kg body weight (BW). Data for serum cortisol concentrations showed a great deal of individual variation. A transient increase in cortisol was observed, but only in the group treated with 1,000 micrograms pGH/kg BW. Cortisol levels returned to baseline 2 h after pGH injection.(ABSTRACT TRUNCATED AT 250 WORDS)